1. _Agriculture or crop moving._--When the crops are ready to be garnered labor must be imported at any cost. The leading crops in these seasonal demands are grain harvesting, corn shucking, fruit picking, potato digging, beet topping, cotton picking, hop picking, etc. If a man follows the wheat harvest, he may be occupied from the middle of June when the crop is ready in Oklahoma until November or December when the season ends with threshing in North Dakota and Canada. Workers who pick fruit may remain in one locality and have some kind of fruit always coming on. 2. _Building and construction work._--Next to crop moving the building trades and construction jobs make the heaviest seasonal demands upon the labor market. Railroad construction, ditch digging, and similar occupations are generally discontinued during the winter. Carpentry, masonry, brick and concrete work are only carried on with reduced numbers of men through the cold months. 3. _Fishing._--Salmon fishing on the Pacific Coast and oyster fishing on the Atlantic Coast are also seasonal industries. In the fishing industry, as in other seasonal occupations, there is a demand for experienced workers that cannot always be had when most needed. 4. _Sheep shearing._--Sheep shearing is a skilled trade. Thousands of men are needed to harvest the wool crop each year and these men are forced to become migratory. The shearing season, like the harvest, moves from border to border during a period of three or four months. In the Southwest the sheep are sometimes clipped twice a year. The shearing jobs are usually short but lucrative. 5. _Ice harvesting._--Formerly the ice harvest furnished employment to an army of men for two months or more during the winter. Ice-manufacturing plants have diminished the demand for natural ice, though ice cutting still furnishes winter jobs for many men. 6. _Lumbering._--Working in the lumber woods and in the saw mills is not now so much of a seasonal job as it was when the industry centered around the Great Lakes. The industry has gone West or over the border into Canada, where, with the longer winter season and improved facilities, it operates almost all year. It is not necessary in Washington, Oregon, and California to wait for the snow to begin work in the woods as in Michigan and Wisconsin in the early days. Certain occupations not essentially seasonal have a tendency to contribute to migrancy. In many metal mines a man’s health will not permit him to work long. He leaves and goes into some other mine in the same or a different district where the danger is not present. A miner tends to become a migrant for the sake of his health. There are other industries in which hazards exist that force workers to become transient.